1. Field of the Invention
The present invention relates to a display apparatus drive circuit, and in particular, to the display apparatus drive circuit having a plurality of cascade connected driver ICs.
2. Description of the Related Art
In recent years, a display panel grew in size, and attention is given to a display apparatus drive circuit for driving the display apparatus with a plurality of cascaded driver ICs.
As for such driver ICs, the ones shown in FIG. 7 are generally known as the related art (refer to Patent Document 1 for instance)
The driver ICs 701 shown in FIG. 7 are comprised of a phase adjustment circuit 702, a data latch circuit 703, a gray level selection circuit 704 and an output circuit 705.
The phase adjustment circuit 702 receives display data and a clock supplied from an LCD controller not shown and performs phase adjustment, and then conveys the data to a next-stage driver IC and also conveys the data to the data latch circuit 703. Based on the data latched by the data latch circuit 703, the gray level selection circuit 704 controls the output circuit 705 so as to have an unshown liquid crystal display panel driven by the output circuit 705.
As shown in FIG. 8, the phase adjustment circuit 702 is comprised of a flip-flop circuit 801, a PLL circuit (DLL circuit) 802 for generating a clock signal of (π/2) phase difference and a flip-flop circuit 803. The data supplied to the flip-flop circuit 801 is reshuffled with the clock signal, and then the data supplied to the flip-flop circuit 803 is latched with the clock signal shifted by (π/2) so as to adjust a phase shift between the data and the clock.
[Patent Document 1]
Japanese Patent Laid-Open No. 2001-324967